“To build a fire” commonlit answers

Building a fire is an act of technical skill and technology, and fire in literature has also often been used as a symbol of knowledge. The building of a fire thus symbolizes life in the story, but also life through human knowledge, skill, and technology.

The children sailed paper boats before dinner.

Mothers call the children inside when dinner is ready.

She fell while she was playing and injured her knee.

Explanation:

Prepositional phrases are composed at least of a preposition and an object.

The word 'when' used as a conjunction means 'at the time that', and is followed by a subordinate clause.

The word 'while' is used to connect two events occurring at the same time, and is followed by a subordinate clause.